At present, in an evaporation process for an OLED (organic light emitting diode), filling becomes a basic step, in an evaporation process of a traditional large size OLED, after a metal material and an organic material being filled in an atmosphere, then put the metal material and the organic material in an organic chamber for evaporation. However, in the process of evaporation, the organic material is easy to react with oxygen and water vapor in the atmosphere, and the organic material is easily deliquesces at the same time of oxidation and the purity of the organic material is affected. Especially the active metal material is too active, an oxide layer is easy to form on the surface of a metal ball or a metal block, and the oxide layer is unfavorable for an evaporation electrode, an evaporation temperature is increased while the purity of an evaporation metal is declining. For example, in the preparation of the WOLED (white organic light emitting diode), n-CGL (n type doping charge generation layer) often uses lithium metal doping, lithium is easy to react with oxygen and nitrogen in the atmosphere to form lithium oxide and lithium nitride. To solve the problems that exposed in air, a method of manipulator filling in the vacuum is usually used, or the method of shorten the filling time as much as possible is used. However, the mechanical filling equipment used in the first method is expensive and complex, and greatly increases the cost; the second method just shortens the time of contacting with the atmosphere and cannot solve the problem of metal oxide in a thorough way.